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2 Sheets-Sheet 1. G. HUMMEL.

WATT METER (No Model.)

No. 570,019. Patented oct. 27, 1896.

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2 sheets-Sheet 2i" G. HUMMEL. WATT METER (No Model.)

10.570,019.- f Patented out. 27, 1896.

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` UNITED l STATES 'PATENT OFFICE;

GEORG HUMMEL, OF MUNICH, GERMANY.

WATT M ET E R SPECIFICATION forming part of Letters ,Patent No. 570,019,l dated October 27, 1898.

Application led January 30, 1895. Serial No. 536,743. (No model.) Patented in Switzerland December 2'7, 1894, No. 9,812 i in Italy February14, 1895, XXIX, 38,094, LXXIV, 408;

in France April 30, 1895, No. 244,481; in Hungary June 22,

1895, No. 3,074, and iu Austria. September 20, 1895, No. Itil/3,422.

form of electric motor intended especially for the driving of Wattmeters or other apparatus designed to accurately measure alternati-ng or pulsating currentsof electricity;' and to this end it consists in the mechanism hereinafter described, the novel features of which are particularly pointed out inthe claims at power, while having alsoother theoretical the end of this specification.

The invention disclosed and claimed in the present application has been patented to me in the following-named cour ries, to wit: Italy, Reg. Gen.,Vo1. XXIX, No. 38,094, Reg.

'Att., Vol. LXXIV, N o. 408, dated February which- Figure l is a longitudinal sectional View of my improved meter-motor, showing theV circuits in diagram; and Fig. 2 is a transverse sectional View of the same, taken on the broken line 2 2, Fig. 1, and as seen looking from the'top toward the b ottom ofthe draw ling in the'direction of the arrows upon that figure. Fig. 3. is a 'similar view to Fig.l 2, illustrating the complete winding for a motor having a held-magnet with four pole-pieces;

and Fig. 4 is a diagrammatic View i1lustrating an alternating or pulsating current electrical generator of well-known form and a pair of current-mains with my improved wattmeter-inotor and a series of electrical translating devices connected in circuit there- Furthermore, M. Blathy, for the same purpose, devised a motor inI which two phases are utilized in separate magnetic circuits. Vhile M. Blathy has thus utilized the principle referred to inthe driving of an electric aware, has been attained during the last decade in the application of Ferrariss principle in the construction of electric meters. reasons for this are not difficult to ascertain.

oretical characteristics, but isV not really named. I have directed iny attention to the construction of a motor of essentially greater characteristics, and have arrived at the conviction that this end cannot be attained without the use of iron in the motor. By the use of iron, it is true, a different inode of operation is in eifect created. The viewsof Ferarsare able losses in eEect as well as the changeableness of the permeability of iron at different demands exert an in uencediiicult to determine in advance. This iniluenee' is about com parable with that which the' employment of iron would bring about in wattmeters. 'I have, nevertheless, discovered that in spite of these various influences the desired eect can be obtained if, in addition to the iron as a magnetic conductor common to both phases, --a correspondingly long air interval for the magnetic path be. used. In accordance with this principle of construction my improved meter-motor is constructed.'

Referring now tothe drawings in detail, the inducing as well the induced-field is of iron E and E', the inducing-held E beingpreferabl y of Gramme-ring multipola'r form, having internally-projecting pole-pieces e e, four in number, as 'shown in Figs. 2 and 3. Between the inducing and induced fields is iuterposedjan interval which consists in part sesses a resistance vso considerable that the effect of the iron almost'disappears. trast to the principlesof construction of the4 latest formsjof alternating-current motors the electric circuits of the ,armature in my meter, no practical success, so faras I am The Ferrariss motor has, it is true, excellent the- -practically available for use in the manner not strictly correct. Moreover, the' unavoid- Y f of air and in part of copper, and 'thus pos- 95 In conl invention consist oi' a relatively thick walled copper or diamagnetic cylinder or bell C,ind side of which is located a stationary iron armature E', and corresponding to its thiclness the resistance of the magnetic circuit is increased. This copper cylinder or bell is attached to a vertically-disposed shaft D, journaled at el d, m being aretarding-disk and M a retarding-magnet of well-known 1o form, the shaft D being geared to registering apparatus or other apparatus to be driven in any preferred manner. rlhe copper cylinder or bell C, carried by the vaxis D, moves4 between the inducing-magnet system and the stationary iron armature E.. The winding of the motor consists of two parts: first, the

field-conductor'R, through which all of the current to be measured flows, this part of 3o and g g the current-collecting brushes connected to current-mains Aw w Zlbcing incandescent lamps, l Z arc-lam ps, and M M alternating'- current motors or other electrical translating devices connected in multiple be- 3 5 tween the current-mains.

, L is an inductive resistance or condenser designed to shift 'the current phase of the 4shunt-circuit N as far as possible (about "f ninety degrees) toward that of the current 4o in a resistance devoid of induction.

The theory of my improved apparatus is based upon the following considerations: The `draft Z which the armature of a twophase motor, with two phases ninety degrees apart, exerts is Zzcl lz'- J cos. (/2, wherein t' indicates the current strength of one circuit (say the shunt circuit) and J the current strength of the other circuit, (say the main circuit.) c, is any desired constant; 75, the

5o phase shift of the main current with. respect to a current in a resistance entirely free from induction. It is apparent, therefore, that this draftwill become the smaller the greater the phase shift of the main current. It will become nil' if d equals ninety degrees. The

above equation properly interpreted corresponds to that of a wattmeter. In the latter, however, the phase of the shunt-current toward a'current in a resistance free from in 6o duction is not shifted.

The work which the'niotor produces when the number of revolutions is equal to n and which corresponds to the draft Z is A=Z n: c1 z' J cos. n. On the other hand, the work 65 which is consumed in l,the copper disk becomes Agia", vi2 ilu-:21%, wherein 2 indicates the current arising in the copper disk during rotation; E, the tension'corresponding thereto; w, the `resistance of the conductors 1n which this current passes.' Now, as is appre- 2 c1able, w '2:{130-:63 or. Since A, must equal A2 in so far as losses in effect are not taken account of, now c, fi J cos. r orzo, n2, or c1 t J cos. =c3 a.

It being presupposed that losses in effect do not come into consideration and that t is shifted ninety degrees toward a current in ind uctionless resistance, the numberof revolutions of the present system is therefore exactly proportional to the electrical work c1 t' .I cos. which is to be measured.

Although I have described my invention as applicable to watt and other electrical measuring meters, it is obvious that it might be used anywhere in the art where alternating-current motors are utilized.

Havingthus described my'invention, what- I claim, and desire to secure by Letters Patent of the United States, is-

l. An alternating-current motor provided with a stationary held-magnet having pairs of internally-projecting field-magnet poles surrounded with field-magnet windings connected directly to a source of alternatingcurrent supply, an additional field-magnet winding of higher resistancel than the first field-magnet winding and located in shunt relation thereto, and an induction device located in said shunt for shifting the current phase inl combination with a rotary part consisting of diamagnetic material such as copper and a fixed stationary part concentric with said rotary part, said stationary part being of magnetic materiahand both o f said parts being located wholly in the inductive field of all of the pole-pieces, whereby the inducing and induced effect is substantially the same.

A' wattmeter-moter provided with two sets of windings forv the fixed or stationary portion thereof, one set of said windings be-- ing disposed upon a field-magnet core having internallyprojecting pole-pieces and the other upon an independent frame or support in combination with a cylindrical diamagnetic ICO rotary part and a fixed or stationary cylindrical' magnetic part, both of said parts being concentric with the curvature of the inner ends of the field-poles and located wholly in the magnetic iniuence thereof.l

3. An alternating-current motor provided with a rotary part of diamagnetic material, in combination with two sets of field-magnet poles surrounding said rotary part, and a fixed or stationary concentric cylinder of magnetic material located within said rotary part, said concentric cylinder lying wholly in the mag, netic field of all of said poles whereby the inducing and induced effect is substantially the saine.

4. A wattmeter-motor having a propelling part in the nature of a diamagnetic cylinder,

IZO

a field-magnet or stationary part surrounding sald cylinder and provided with energizingcoils connected in circuit with the current to `be.measured, and a stationary magnetic cylindrical part located within the diarnagnetic cylinder and lying Wholly within the magnetic eid of all of the field-magnet poles, whereby the inducing and induced effect is substantially the same. i

. 5. A Wattmeter-motor having energizingcoils located in one branch of the circuit, the

current of which is to be measured, a second energizing-coil located in multiple arc with the translating devices, said second coil being of higher resistance than the first-named coils; a rotary part consisting of a diamagnetic cylinder and a stationary cylindrical part of magnetic material located inside the rotary part, in combination with an induction device located in circuit with the second energizingvcoil said cylindrical parts' lying at all times wholly Within the magnetic field, whereby the inducingand induced eect is approxi mately the same; substantially as described.

6. An alternating-currentmotor provided with a field-magnet core of cylindrical form 'having pairs of internally-projecting polepieces, and coilsor windings connected in circuit with a current-main; additional iieldmagnet Windin gs of a relatively greater number of coils and connected in multiple with translating devices between the currentmains, a cylindrical rotary part of diamagnetic material having its exterior surface in close proximity to the magnetic eld of both 'sets of held-magnet poles, a fixed or stationary cylindrical magnetic part concentric with the diamagnetic armature, the arrangement being such that the inducing and the induced eect is substantially the same.

In testimony whereof I have hereunto subscribed my name this 27th day of December, 1894.

GEORG HUMMEL.

lVitnesses:

EMIL HALZENBEBGER, H. KURTH. 

